This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. This study will evaluate the safety and efficacy of islet after kidney transplantation (IAK) in patients with type 1 diabetes. Patients must have previously received successful renal transplant with stable immunosuppression consisting of sirolimus, tacrolimus and no corticosteroids and be referred by a transplant nephrologist/surgeon. Islets will be transplanted intraportally. Patients will be monitored closely for two years for the occurrence of adverse events and changes in renal graft function, blood glucose control, insulin dose requirements, other metabolic variables, immunologic reactions and quality of life. Islet transplantation is expected to improve glycemic control and thereby improve the patient's renal graft function and quality of life.